Fix for ECC sign with hardware to ensure the input is truncated to the key order.

This commit is contained in:
David Garske
2019-02-22 15:29:45 -08:00
parent 9c9221432f
commit 712ecabf36

View File

@ -4239,13 +4239,25 @@ static int wc_ecc_sign_hash_hw(const byte* in, word32 inlen,
#endif
{
word32 keysize = (word32)key->dp->size;
word32 orderBits;
DECLARE_CURVE_SPECS(curve, 1);
/* Check args */
if (keysize > ECC_MAX_CRYPTO_HW_SIZE || inlen != keysize ||
*outlen < keysize*2) {
if (keysize > ECC_MAX_CRYPTO_HW_SIZE || *outlen < keysize*2) {
return ECC_BAD_ARG_E;
}
/* if the input is larger than curve order, we must truncate */
ALLOC_CURVE_SPECS(1);
err = wc_ecc_curve_load(key->dp, &curve, ECC_CURVE_FIELD_ORDER);
if (err != 0)
return err;
orderBits = mp_count_bits(curve->order);
if ((inlen * WOLFSSL_BIT_SIZE) > orderBits) {
inlen = (orderBits + WOLFSSL_BIT_SIZE - 1) / WOLFSSL_BIT_SIZE;
}
FREE_CURVE_SPECS();
#if defined(WOLFSSL_ATECC508A)
key->slot = atmel_ecc_alloc(ATMEL_SLOT_DEVICE);
if (key->slot == ATECC_INVALID_SLOT) {